1. Technical Field
The present invention generally relates to fuel delivery systems and, more particularly, to a dual function fuel supply module.
2. Technical Field
Internal combustion engines require fuel in the form of gasoline or diesel for operation. A fuel delivery system is required to deliver the fuel from a storage location such as a fuel tank to the internal combustion engine. According to the prior art, three primary fuel delivery systems are provided.
According to a first fuel delivery system, a mechanical gear pump is coupled to the internal combustion engine which drives the pump and draws fuel from the tank to the engine. According to a second system, an electric pump is disposed along a fuel line between the fuel tank and the engine. Upon receipt of an applied current, the electric pump operates to deliver fuel from the fuel tank and deliver it to the engine. According to a third system, an electric pump is disposed within the fuel tank. Upon receipt of an applied current, the fuel pump operates to deliver fuel from the fuel tank to the engine.
Direct injection fuel systems use a mechanical gear-driven pump as part of the high pressure system. Unfortunately, the mechanical pump is not able to prime itself after running dry or after initial installation. Dry operating conditions include first start conditions at the assembly plant, an operator running out of fuel, and breaking into the system for service.
Thus, it would be desirable to provide a fuel delivery system which utilizes a mechanical gear-driven pump in combination with electric pump for fulfilling priming needs.